Although Y-HPC, Terra Soft’s cluster-oriented distribution, has supported 64-bit processing for a while, their Yellow Dog Linux distribution has stayed 32-bit, even when running on 64-bit hardware like the Apple G5. Terra Soft has now “given into peer pressure” and released a 64-bit YDL, with support for 16GB of RAM and a bi-arch toolchain (which can produce both 32- and 64-bit binaries).